First, a night shot of the Loud Dam and Au Sable Water and Power in place on my layout addition.
Next, a light-leak solution that was pretty quick and easy. It's not perfect, but it really helps cut down on unwanted light rays coming from under structures. These houses are HO, and in the first pic, you can see the problem.
So I made up these 3/16" Masonite bases that just fit inside the buildings. The one inch hole is a nest for the light bulb, and I put a diffuser over the opening.
In the next image, one of the bulbs is covered. When no light emits from under the base, I put the structure over it.
Much improved... Hope this might work for you, too. EK